Highway maintenance vehicle



FIG. 1 is a perspective view showing the front end and left side of ahighway maintenance vehicle, of my new design;

FIG. 2 is a perspective view showing the rear end and right sidethereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side elevational view thereof; and

FIG. 5 is a left side elevational view thereof.

The ornamental design for a highway maintenance vehicle, substantiallyas shown.